a ray on the positive x-axis is rotated -450°. what is the cosine of the angle formed by this rotation?
To find the cosine of the angle formed by the rotation of -450°, we need to determine the equivalent angle within one full rotation.
-450° is equivalent to -450° + 360° = -90°, since it takes 360° to complete one full rotation.
The angle formed by this rotation is -90°.
Using the unit circle, we can find the cosine of -90°.
For cosine, we evaluate the x-coordinate of the corresponding point on the unit circle.
On the unit circle, the point corresponding to -90° has an x-coordinate of -1.
Therefore, the cosine of the angle formed by this rotation is -1.